The relationship between blood pressure variability, obesity and left atrial phasic function in hypertensive population

We sought to investigate the relationship between blood pressure (BP) variability and left atrial (LA) phasic function assessed by volumetric and speckle tracking method in normal-weight, overweight and obese hypertensive patients. This cross-sectional study included 164 untreated hypertensive subjects who underwent a 24-h ambulatory BP monitoring and complete two-dimensional echocardiographic examination (2DE). All the patients were separated into three groups according to their body mass index (BMI): normal-weight patients (BMI < 25 kg/m2), overweight patients (25 ≤ BMI < 30 kg/m2), and obese patients (BMI ≥ 30 kg/m2). Daytime, nighttime and 24 h BP variability indices were higher in obese hypertensive subjects than in lean patients. Maximum and minimum LA volumes and volume indexes gradually and significantly increased, whereas pre-A LAV decreased, from normal-weight to obese subjects. Total and passive LA emptying fractions, representing LA reservoir and conduit function, gradually reduced from lean to obese individuals. Active LA EF, the parameter of LA booster pump function, increased in the same direction. Similar results were obtained by 2DE strain analysis. BP variability parameters were associated with structural, functional and mechanical parameters of LA remodeling in the whole study population. The parameters of LA reservoir function were negatively related with BP variability indices, whereas the parameters of LA pump function were positively related with BP variability indices. Obesity significantly impacts BP variability and LA phasic function in untreated hypertensive subjects. BP variability is associated with LA remodeling independent of BP, left ventricular systolic and diastolic function.